Please tell me more about how I've deceived myself.
Just as the MMR vaccine is less about you contracting measles and more about your spreading measles to more vulnerable populations that are unable to get the vaccine, the flu shot is identical in that regard. Sure, it helps you not get sick and/or to lessen the effects, but there is the fact that some portion of the population is unable to get the shot for various health reasons.
Edit: Instead of downvoting please tell me how my experiences are wrong. I'm very much aware of evidence and studies stating that its "impossible" to get the actual flu from the flu shot, yet I am walking proof of contrary evidence. I'm also aware of how batshit emotional people can get with regards to vaccines, and I want to be clear I am absolutely NOT advocating that anyone forgo getting a flu shot every year. When everyone else gets the shot, I'm safer. When I get the shot, my body reacts violently and I will contract the virus.